In recent years, in a field of display units performing image display, a display unit (an organic electro luminescence (EL) display unit) using, as a light emitting element, a current-driving optical element whose light emission luminance is varied in response to a value of a flowing current, for example, an organic EL element, has been developed and commercialization thereof is progressing. Unlike a liquid crystal element or the like, the light emitting element is a self light-emitting element, and a light source (a backlight) is unnecessary. Therefore, the organic EL display unit has characteristics of high visibility of an image, low power consumption, high response speed of an element, etc., as compared with a liquid crystal display unit demanding a light source.
In the display unit, drive circuits control pixels arranged in a matrix. For example, in PTL 1, a display panel including a shift register and a drive scanner that includes inverters connected to respective output terminals of the shift register is disclosed.